/Engine/Source/Runtime/Experimental/Chaos/Public/Chaos/Collision/CollisionConstraintFlags.h
Add an ignore entry for collisions of Particle0->Particle1. Note, this will add an entry for both particles against the other if both particles are dynamic or kinematic.
void AddIgnoreCollisions ( [FGeometryParticleHandle](API\Runtime\Chaos\Chaos\FGeometryParticleHandle) * Particle0, [FGeometryParticleHandle](API\Runtime\Chaos\Chaos\FGeometryParticleHandle) * Particle1 )